biphenylene+CH3 C13H10
A2_3a2982dd85 · SMILES Cc1ccc2c(c1)-c1ccccc1-2 · InChIKey NHXQGCXQYYKWBN-UHFFFAOYSA-N
Cheap level done
analytic Hessian
screened (large B3LYP → ωB97X shift) → finite-difference Hessian was noisy → release uses the analytic Hessian. The two functionals differ by more than 80 cm⁻¹ on some frequency, which sent the molecule to the analytic second route (screen of 23 Sep 2026). The finite-difference Hessian and the analytic Hessian of the same geometry differ by more than 15 cm⁻¹ on at least one frequency; the numerical route is the noisy one. In the released training set this molecule carries the analytic Hessian instead of the finite-difference one.imaginary mode healed
imaginary mode healed by the analytic Hessian. The finite-difference Hessian showed an imaginary frequency that the analytic Hessian does not: numerical noise, not a saddle point.Harmonic frequencies at the cheap level (deck v1: B3LYP and ωB97X, 6-31G*, at the B3LYP geometry)
63 vibrational modes; imaginary modes negative. Shift = ωB97X − B3LYP.
Band heights are not computed for this molecule yet (no dipole derivatives); positions only, at unit height. High wavenumbers on the left; the table below is the same data.
| # | B3LYP (cm⁻¹) | ωB97X (cm⁻¹) | shift |
|---|---|---|---|
| 1 | 82.0 | -36.9 | -118.9 |
| 2 | 84.4 | 97.6 | +13.2 |
| 3 | 142.9 | 156.2 | +13.3 |
| 4 | 181.3 | 189.6 | +8.3 |
| 5 | 217.4 | 223.8 | +6.3 |
| 6 | 339.2 | 341.7 | +2.6 |
| 7 | 348.7 | 358.9 | +10.2 |
| 8 | 379.2 | 383.6 | +4.4 |
| 9 | 395.7 | 406.4 | +10.7 |
| 10 | 445.9 | 442.3 | -3.7 |
| 11 | 490.8 | 503.1 | +12.3 |
| 12 | 552.6 | 558.0 | +5.4 |
| 13 | 588.1 | 590.3 | +2.3 |
| 14 | 602.4 | 617.3 | +14.9 |
| 15 | 630.9 | 635.8 | +4.9 |
| 16 | 690.1 | 698.0 | +7.9 |
| 17 | 718.3 | 737.4 | +19.1 |
| 18 | 756.4 | 772.0 | +15.6 |
| 19 | 788.8 | 797.1 | +8.4 |
| 20 | 817.5 | 830.6 | +13.1 |
| 21 | 831.8 | 852.6 | +20.8 |
| 22 | 853.4 | 863.5 | +10.1 |
| 23 | 889.1 | 910.9 | +21.8 |
| 24 | 902.1 | 925.9 | +23.8 |
| 25 | 920.0 | 953.0 | +33.0 |
| 26 | 933.3 | 966.2 | +32.9 |
| 27 | 969.8 | 997.3 | +27.5 |
| 28 | 996.0 | 1005.0 | +9.0 |
| 29 | 1012.2 | 1017.2 | +5.1 |
| 30 | 1020.0 | 1023.5 | +3.5 |
| 31 | 1059.5 | 1069.1 | +9.6 |
| 32 | 1074.9 | 1081.1 | +6.2 |
| 33 | 1080.2 | 1092.0 | +11.7 |
| 34 | 1136.6 | 1142.9 | +6.3 |
| 35 | 1139.4 | 1149.8 | +10.4 |
| 36 | 1149.7 | 1154.7 | +5.0 |
| 37 | 1195.9 | 1190.7 | -5.2 |
| 38 | 1215.0 | 1221.9 | +6.9 |
| 39 | 1307.9 | 1286.3 | -21.5 |
| 40 | 1319.8 | 1319.9 | +0.1 |
| 41 | 1320.2 | 1323.6 | +3.4 |
| 42 | 1427.2 | 1438.5 | +11.3 |
| 43 | 1443.6 | 1451.3 | +7.7 |
| 44 | 1462.8 | 1478.4 | +15.5 |
| 45 | 1486.5 | 1505.7 | +19.3 |
| 46 | 1494.2 | 1509.7 | +15.5 |
| 47 | 1513.2 | 1514.0 | +0.8 |
| 48 | 1521.1 | 1533.9 | +12.8 |
| 49 | 1534.5 | 1547.3 | +12.8 |
| 50 | 1642.8 | 1681.5 | +38.8 |
| 51 | 1648.2 | 1693.0 | +44.8 |
| 52 | 1662.1 | 1704.5 | +42.4 |
| 53 | 1723.1 | 1750.8 | +27.8 |
| 54 | 3037.8 | 3073.7 | +35.9 |
| 55 | 3086.9 | 3138.0 | +51.1 |
| 56 | 3125.1 | 3172.2 | +47.0 |
| 57 | 3180.7 | 3224.8 | +44.1 |
| 58 | 3182.3 | 3225.6 | +43.3 |
| 59 | 3187.5 | 3231.4 | +43.9 |
| 60 | 3194.9 | 3238.0 | +43.2 |
| 61 | 3203.9 | 3247.2 | +43.3 |
| 62 | 3204.7 | 3247.8 | +43.1 |
| 63 | 3211.2 | 3254.0 | +42.8 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 134 cm⁻¹.
Provenance
- Releases: layerA2_2026-09-24
- Entered the corpus as: substituted three- and four-ring cores, enumerated from the parents (layer A′) (layer A2)
- Run: ubuntu-32gb-hel1-12, 2026-09-22 06:08:27 → 2026-09-22 06:58:48, 3020 s, peak 4.2 GB, deck 97ed2d67c66b
- Imaginary modes: B3LYP 0, ωB97X 1
- Source files: corpus factory · manifest